Display devices using organic electroluminescent (EL) elements or liquid crystal elements have been known. Examples of the display device also include a light-emitting device provided with a light-emitting element such as a light-emitting diode (LED), and electronic paper performing display with an electrophoretic method or the like.
The organic EL element generally has a structure in which a layer containing a light-emitting organic compound is provided between a pair of electrodes. When voltage is applied to this element, light emission can be obtained from the light-emitting organic compound. With use of such an organic EL element, thin, lightweight, high-contrast, and low-power-consumption display devices can be achieved.
Patent Document 1 discloses a flexible light-emitting device using an organic EL element.